Articles subjected to high external temperatures.



JOHN C. HENDERSON, OF WASHINGTON, DISTRICT OF COLUMBIA, ASSIGi-NOE. T0

DRIVER-HARRIS WIRE COMPANY, OF HARRISON, NEW JERSEY, A CORPORA- TION 01EJERSEY.

ARTICLES SUBJECTED TO HIGH EXTERNAL TEMPERATURES.

No Drawing. 7

To'all whom it may concern:

Be it known that I, JOHN C. HENDERSON, a citizen of the United States,residing at Washington, D. C.,'have invented a certain new and usefulImprovement in Articles Subjected to High External Temperatures, ofwhich the following is a full, clear, and

' exact description.

a remarkable extent.

It also has for its object to produce articles which, when in use, willhave remarkable qualities as hereinafter specified.

My invention relates to such cast articles a as molds for die castingand other uses,

valves andvalve seats for internalcombustion engines, crucibles, outercaslngs for crucibles, linings for molds and crucibles, annealing boxes,case hardening or carburizing boxes, articles including tables, molds,plungers and conveyers for use in the working of glass and other massivearticles, and consists of forming such articles from an alloy containingnickel orcobalt and chromium in certainproportions. v The alloy requiresa very high melting heat, but when once sufliciently melted can be castin the ordinarymanner. H

In carrying out my invention I use an alloy containing from 5 to v30 percent. of chromium and from to 90 per cent. of nickel (or cobalt), thecombined nickel (or cobalt) and chromium being at least per cent. andthe greater part of the remainder being of iron. The following is thepreferred composition of the alloy used in carrying out my invention,viz.nickel 60 per cent., iron 26 per cent, chromium 12 per cent,manganese 1:} per cent. When the article is to be machined the alloyshould be substantially carbon-free, the carbon not exceeding .40 percent. Iron, nickel and cobalt belong to the same group of metals inMendeleefs table and have approximately the same atomic weights, to wit,iron 55.85, nickel 58.68, and cobalt 58.97 and cobalt may.

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' be substituted for nickel in carrying out my invention, since it hassubstantially the same properties as nickel.

In forming an article such as a valve according to my invention, I firstcast'a blank composed of the alloy above referred to and then machine itor grind it into proper shape. In forming annealing boxes, casehardening or carburizing boxes, the boxes may be cast without requiringsubsequent machining of their surfaces.

Internal combustion engine valves formed according to my inventiondo'not become pitted-or c'orrodedor Warped, so as to re quire frequentscraping or periodic regrinding, as is the case with valves as atpresent made.

Molds embodying my invention are not liable to serious oxidation orother injury when used in casting brass or other similar metals and areso strong that they can be used for long periods for die casting. Theyproduce smooth castings for the reason that the surface remains smootheven under the trying conditions of temperature changes and hightemperatures, and they resist chemical actions to which old types ofmolds are liable. On account of their low heat conductivity they preventthe castings from chilling beforeremoval, thereby producing castings ofmaterials such as iron that can be easily machined.- Molds embodying myinvention are particularly useful in the manufacture of glass articles,such as glass bottles, since they withstand the high temperature andabrasion to which they are subjected in a remarkable manner and producemore highly polished glassware because they can be used at a highertemperature than other materials without the glass sticking or adheringthereto, and also resist the chemical. action due'to the constituents ofglass. On accountof the strength of the material they can be made muchlighter than castiron molds.

Tables, rolls, drawing dies for glass Working when made according to myinvention are so slightly oxidized or corroded when in use that they canbe used for a very long time without refinishing. Conveyer links forconveyors employed in moving or transmitting hot sheets of glass arealso remarkably enduring when made according to my invention.

Crucibles when made according to my invention easily withstandtemperatures sufiiciently high for melting of brass or other materialsof similar high melting point and are substantially unaffected by themolten metal. \Vhile the alloy specified is of relatively low heatconductivity when compared .with other alloys or metals, it is of muchhigher heat conductivity than graphite or magnesite heretofore used inthe construction of crucibles, so that for this reason and also for thereason that the crucible, when made according to my invention, may bethinner than crucibles heretofore used, the contents of the crucible canbe more quickly brought to the melting point. The material of thecrucible does not affect the quality of the molten content. Furthermore,crucibles made according to my invention can be heated and cooledquickly without dama e to the crucible so that with crucibles em odyingmy invention not only can a purer product be obtained, but a greatsaving in time can be achieved. A very considerable saving can also beachieved by reason of the fact that the crucibles are not liable to bebroken and retain their strength when heated to temperatures that woulddestroy ordinary iron or steel. Moreover, the stock or cruciblesnecessary to be kept on hand can be much smaller. The same is true ofthe stock of molds for glass making and annealing boxes. In glassmaking, as heretofore practised, the renewal of molds is necessarilyfrequent and necessitates the stopping of the glass casting machine,resulting in a great loss of time, which is saved by using moldsembodying my invention, and the doing away with the necessity offrequent refinishing of the molds by the use of my invention results ina further great saving of labor and expense.

The manganese appearing in the preferred form of the alloy as abovespecified is not essential in producing my results but is merely theremnant of manganese used in forming the alloy. Where the article in itscourse of manufacture is to be machined, the carbon should preferablynot exceed .40 per cent., but where the article is cast and does notrequire machining, it may be considerably higher, such for instance, as2 per cent.

When subjected to oxidizing atmosphere of high temperature, a slightfilm of oxid forms on the surface of the article which is strong anddurable and strongly resistant easily machined and may be rolled andforged.

What I claim is:

1. A cast article of manufacture subjected when in use to external heatat high temperatures composed of an alloy containing chromium and ironand another metal of the iron group of substantially the same atomicweight as iron, the chromium being from 5 to 30 per cent. and the metallast referred to from 50 to 90 per cent., and the combined third metaland chromium amounting to at least 60 per cent.

2. A cast article of manufacture subjected when in use to external heatat high temperatures composed of an alloy containing nickel and chromiumand iron, the chromium being from 5 to 30 per cent., and the nickel from50 to 90 per cent., and the combined nickel and chromium amounting to atleast 60 per cent.

3. A cast article of manufacture subjected when in use to external heatat high temperatures composed of a ferrous alloy containingsubstantially chromium 12 per cent., iron 26 per cent., and 60 per cent.of another metal of the iron group of substantially the same atomicweight as iron.

4:. A cast article of manufacture subjected when in use to external heatat high temperatures composed of an alloy containing chromium and ironand another metal of the iron group of substantially the same atomicweight as iron, the chromium being from 5 to 30 per cent., and the metallast referred to from 50 to 90 per cent., and the combined third metaland chromium amounting to at least 60 per cent., the alloy beingsubstantially carbon-free.

5. A massive article of manufacture subjected when in use to externalheat at high temperatures composed of an alloy containing chromium andiron and another metal of the iron group of substantially the sameatomic weight as iron, the chromium being from 5 to 30 per cent., andthe metal last referred to from 50 to 90 per cent., and the combinedthird metal and chromium amounting to at least 60 per cent.

6. A cast internal-combustion-engine valve subjected when in use toexternal heat at high temperatures composed of an alloy containingchromium and iron and another metal of the iron group of substantiallythe same atomic weight as iron, the chromium being from 5 to 30% and themetal last re ferred to from 50 to 90% and the combined third metal andchromium amounting to at least 60%, the alloy being substantially carbonfree.

JOHN C. HENDERSON.

